Device for eliminating the transmission of extraneous noises in telephone circuits



Oct. 28, 1930-. o. A. BULKELEY 1,779,461

DEVICE FOR ELIMINATING THE TRANSMISSION OF EXTRANEOUS NOISES IN TELEPHONE CIRCUITS Filed June 11, 1929 Patented Oct. 28, 1930 UNI En ,sT ss crnunn A. BULKELEY, on KENMORE, NEW-YORK it I DEVICE non nnriumiirme THE rminsmissroiv or I ,TELEPHONE cincurrs Application filed June 11,

This invention relates to a device for eliminatingthe transmission ofextraneous noise over telephone circuits, and more particularly to a device which is'adapted'to be attached to any standard telephone transmitter and which when applied eliminates the buzzing or rushing sound heard in a telephone receiver due to the noise in the room or locality in which the telephonetransmitting instrument and the receiver is located; I The principal object of this invention is therefore to provide a simple, inexpensive'd'e vice of this character which can be attached to any standard telephone transmitter and inated by the present inventionis heard in' the receiver of the transmitter affected by the extraneous noise, i. e., in'the receiver located in theroomwhere the extraneous vnoise causing. the buzzing or rushing sound exists. In theaccompanying drawings: Figure 1 is afragmentary front-view of a telephone transmitter 3 showing my inven tion applied thereto. V g

Figure 2 is aside view thereof. 7

Figure 3' is a perspective view of my'invention detached from a telephone, showing the position of its parts when applied to a telephone. 7 y 3 Figure 4 is a side elevation of my invention showing the position of the parts before it is applied to atelephone.

Similar reference numerals'refer to similar characters in the several figures of'the drawings:

The telephone shown in the drawings is of standard form and includes. a standard 5 carrying a pivot pin 6 on which'the transmitter casing section 7 is plvotally mounted so that the transmitter housing can be moved to any desired angle relative to the stand. The transmitter casing section 7 is bell shaped I iixrnmrzotislfliioisnsin 192e,] seal 1%; 369,948.

iso en' t its front end," thecasing sec-' 7 tion belng closed by a front coverxplate 8 which secured in any suitable manneras:

by screws L received in slots atthe edge of the transmitter casing section. At the 'cenl ter of the front cover plate 3 the usual thread ed opening is providedin-which is screwed the usual hard rubber. mouthpiece -10. The

electrical mechanism for transmitting sounds directed into the mouthpiece 10 is carried by the frontplate' 8 and is housed within the transmitter;casing-"section 7. This mechanism: includes the usual diaphragm- (not shown) which is disposed ilnmediatelybehind the front'plate 8 so thatthe sound Vi brations from the mouthpieceivibrate this Ithas been found that extraneous sound vibrations in the room where 'thetransmit ting instrument and itsreceiver are located, strikelthe front casing plate 8 of the trans- Initterj housing :and this vibration of the transmitter cover plate 8sets up. a vibration ofthe in the 'transmitterhousing which results n an undesired *vibraaenor the tdi a- P phragm and a buzzlng O I'ITIUShIDg 'noisebe ing transmitted to the receiver forming "a part of the instrument of the transmitter affected byvthe extraneous noise and located in the same room. It ha's been found that a device whichf 'exerfs a yielding pressure on the outer: face of thetransmittergcover plate I8 and 7 against therear face of the transmitter casingsection i will prevent its vibration under extraneous sound'vibrations and hence eliminate";the buzzing: or rushing sound heard inthefreceiver of the telephone :set being usedin the rooml where the extraneousnoise exists; Adevice for accomplishing this is. constructed in accordance with l the present invention as follows L The numeral 11 represents a pieceof Wire U-sha'ped part 12, the upper endsor legs of which terminate two spring loops 13. The front U-sh aped part 12 is sufiiciently wide to receive the neck of the mouthpiece 10 and the spring l0opsf13 are positioned so as to be arranged over'the transmitter casing section 7, and the lower endofthe front which is bent to provide a depending" front U-shaped part arranged under the mouthpiece 10. The other ends of each of the spring loops 13 extend downwardly to form two legs 14. These legs are preferably held in proper spaced relation by a wire link 15, which is preferably made in the form of a metal band so that the name of the manu faoturer or other markings can be impressed on the same. At the lower end of the front- U-shaped part 12 a rubber button orpresser member 16 is secured and a similar rubber button or presser member 17 is secured to the lower end of each of the legs 1%. These rubber buttons or presser members may be attached to the wire in any suitable manner, but the wire is preferably deformed at the places of attachment and the rubber buttons are moulded to the deformed parts.

To attach the device to the telephone transmitter, the mouthpiece 10 is preferably first removed and the attachment, as illustrated in Figure 3, is slipped over the transmitter housing so that the front rubber button or presser member bears against the front cover plate 8 at a place immediately below the mouthpiece hole and within the margin of the front cover plate 8, and the legs 14 are disposed. on opposite sides of the neck of the transmitter housing and the rubber presser members 17 carried thereby bear against the lower rear face of the transmitter casing section 7 on opposite sides of the rubber button 16. The front. rubber buttons or presser members 16 are also preferably so. disposed that they bear against the under side of the mouthpiece 10 when the mouthpiece is replaced. WVhen the mouthpiece is so replaced the telephone is ready for operation and the device functions to eliminate the buzzing or rushing sound occasioned by extraneous noise in the room where the telephone instrument is located.

By reason of the spring loops 13, 13, the rubber presser buttons 16 and 17 are yieldingly held near each other and when the device is applied to a telephone as described, these springs operate to hold the rubber button 16 against the front transmitter cover 8 and the button 17 against the rear side of the transmitter casing section 7 and hence prevent the transmitter cover plate and the casing section from vibrating in response to extraneous noises. Thiscuts out the corresponding vibration of the diaphragm and hence eliminates the buzzing or rushing noise frequently encountered in the receivers of telephone instruments located in noisy rooms which buzzing or rushing noise is caused by the vibration of the transmitter housing by the extraneous sounds in the noisy room and'this device therefore makes the conversation more clear and the trans,- mission. more pleasing.

This invention therefore provides a device-for eliminating disagreeable sounds in the receiver of a telephone located in a noisy room, which device is inexpensive to manufacture, easily applied to standard transmitters, and will not get out of order.

I claim as my invention:

1. A device of the character described, comprising a presser member and means for yieldingly holding said presser member against the front face of the cover plate of a telephone-ti'ansmitter at a place within the margin thereof, whereby a constant pressure is'exerted againstsa-id front face toelim-inate thetransmission of extraneous noises.

2, In combination with a telephone transmitter having a casing section, a front cover plate enclosing said casing section andthe electrical transmitting mechanism in said casing section and a mouthpiece carried; by

said cover plate, a resilient presser member and means for yieldingly holding said.-

presser member against the front face of said cover plate at a place within the margin of said cover plate, whereby a constant pressure is exerted against said front face to eliminate the transmission of extraneous noises.

3. A device of the characterv described, comprising a pair of presser members at least one of which is made of resilient material, and means for yieldingly V holding said presser members against the front and rear sides of a telephone transmitter housing.

4. In combination with a telephone transmitter having a casing section, a front cover plate enclosing said casing section and the electrical transmitting mechanism in said casing section and a mouthpiece carried by said. cover plate; a pair of resilient presser members and means for yieldingly holding one of said presser members against the rear side of said casing section and the other presser member against the front face of said cover plate at a place within the margin of said cover plate.

5. A device of the character described for use in connection with a'telephone transmitter, comprising a spring member adapted to embrace the transmitter housing and a pair of resilient presser members "carried by said spring member and urged by said spring member against opposite sides of said transmitter housing.

6. In combination with a telephone transmitter having a casing section, a front cover plate enclosing said casing section and the electrical transmitting mechanism in said casing section and a mouthpiece carriedby said cover plate; a wire'holder having a U- shaped part embracing said mouthpiece, a pair of spring loops at the ends of said U- shaped part, the other ends of said loops being extended inwardly to form legs extending along the rear side of said transmitter housing, a resilientpresser member carried by said U-shaped part and urged against said front cover plateand against a side of said mouthpiece, and a resilient presser member carried by each of said legs and urged against the rear face of saidtransmitter casing section said Wire holder being removable lat- 5 erally from said transmitter. f

In testimony whereof I hereby aflix my sig- 7 nature.

CLAUDE A. BULKELEY. 

